The spatial distribution and migration of three typical fungicides in postharvest satsuma mandarin (Citrus unshiu Marc.) fruit

Abstract

Fungicides are often used to extend the storage time of postharvest satsuma mandarin fruit. In recent years, fungicide residue has become an issue of food safety. This study aimed to investigate the distribution and migration of three typical fungicides (imazalil, prochloraz, thiophanate-methyl) in postharvest satsuma mandarins using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Three fungicides could quickly penetrate satsuma mandarins and their gradient concentrations of residues in the fruit were: carpopodium > mesocarp > epicarp > pulp. However, the residues of three fungicides in the edible pulp were obviously lower than the maximum residue limit (MRL = 5.0 mg kg−1 in China). Residues of the three fungicides decreased in epicarp and carpopodium but increased in mesocarp and pulp during storage. Fungicides could quickly penetrate the fruit, settling primarily in the carpopodium but little in the pulp. Both epicarp and carpopodium were the breakthrough pathways for the fungicides entering the fruit, while epicarp was the main route for the penetration of fungicides. These findings shed new information on the behavior of fungicides and the safety issue of satsuma mandarins.

Actinomycins produced by endophyte Streptomyces sp. GLL‐9 from navel orange plant exhibit high antimicrobial effect against Xanthomonas citri susp. citri and Penicillium italicum

“…Penicillium italicum is one of the main pathogens causing citrus blue mold, which results in significant economic losses during the transportation and storage of citrus fruits after harvest 10 . Prochloraz, imazalil, and mildothane are typical fungicides for the prevention and control of citrus blue mold, but their extensive use has raised increasing worries about pesticide residues, food safety, and the development of fungicide‐resistant P. italicum mutants 11 . Therefore, there is an urgent need to develop novel and safe antifungal agents.…”

“…10 Prochloraz, imazalil, and mildothane are typical fungicides for the prevention and control of citrus blue mold, but their extensive use has raised increasing worries about pesticide residues, food safety, and the development of fungicide-resistant P. italicum mutants. 11 Therefore, there is an urgent need to develop novel and safe antifungal agents. It has been reported that the citrus blue mold can be effectively controlled by some plant essential oils and microbial extracts, which have the potential as alternatives to conventional chemical synthetic fungicides.…”